[flashloan] AaveFlashLoan.available_liquidity ignores paused and frozen reserve flags

[obchain]

Refs #39

File: crates/charon-flashloan/src/aave.rs — available_liquidity()

Problem

The adapter reads the aToken underlying ERC-20 balance to report available liquidity. Aave V3 reserves carry two binary flags that block flash loans regardless of balance:

• paused (bit 60 of configuration word): emergency mode, flashLoanSimple reverts immediately
• frozen (bit 57): no new borrows or flash loans; repayments only

Neither is checked. A paused reserve will report non-zero liquidity, pass the router coverage check, and only fail at the eth_call simulation gate. CLAUDE.md requires all off-chain gates to run before simulation — this gate is defective and passes infeasible routes through.

Impact: Every liquidation routed through a paused Aave reserve fails at simulation, wasting RPC round-trips and widening the liquidation window for competitors.

Fix

Call IPoolDataProvider.getReserveConfigurationData(asset) and check the paused and frozen bits before returning liquidity. Return zero (or FlashLoanError::ReservePaused) when either bit is set. Aave V3 DataTypes.ReserveConfigurationMap encodes paused at bit 60 and frozen at bit 57.

[obchain]

Resolved in b9092e1 on feat/14-flashloan-router. AaveFlashLoan.available_liquidity now calls getReserveConfigurationData and getReserveData on the Aave V3 PoolDataProvider and returns FlashLoanError::ReservePaused when isActive is false, isFrozen is true, or bits 57 (frozen) / 60 (paused) of the packed configuration bitmap are set. Guard runs before the aToken balance check, so a paused reserve fails fast.